CVE-2013-3239 in phpMyAdmin
Summary
by MITRE
phpMyAdmin 3.5.x before 3.5.8 and 4.x before 4.0.0-rc3, when a SaveDir directory is configured, allows remote authenticated users to execute arbitrary code by using a double extension in the filename of an export file, leading to interpretation of this file as an executable file by the Apache HTTP Server, as demonstrated by a .php.sql filename.
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability CVE-2013-3239 represents a critical security flaw in phpMyAdmin versions prior to 3.5.8 and 4.0.0-rc3 that stems from improper file extension handling during export operations. This vulnerability specifically affects installations where a SaveDir directory has been configured, creating a dangerous condition where user-supplied filenames can be manipulated to execute arbitrary code. The flaw exploits the server's file interpretation behavior when files with double extensions are processed, allowing attackers to bypass security measures that would normally prevent execution of php files.
The technical implementation of this vulnerability occurs through a classic file extension manipulation attack vector. When phpMyAdmin processes export files, it does not properly validate or sanitize filenames containing double extensions such as .php.sql or .php.html. The Apache HTTP Server interprets these filenames based on their final extension, meaning a file named .php.sql would be treated as a php file and executed rather than being treated as a sql file. This behavior stems from the server's default handling of multi-part file extensions where only the last extension determines how the file is processed, creating a pathway for code execution that bypasses normal security controls.
The operational impact of this vulnerability is severe and far-reaching for organizations using affected phpMyAdmin versions. Remote authenticated attackers with valid credentials can leverage this flaw to execute arbitrary code on the web server, potentially leading to complete system compromise. The vulnerability allows attackers to upload and execute malicious php code through the export functionality, enabling them to gain unauthorized access to database contents, modify or delete data, and potentially establish persistent backdoors. This represents a privilege escalation scenario where legitimate users can be exploited to perform malicious actions that would normally require administrative privileges.
The vulnerability maps directly to CWE-434, which describes "Unrestricted Upload of File with Dangerous Type," and aligns with ATT&CK technique T1190, "Exploit Public-Facing Application." The attack requires minimal prerequisites beyond having valid authentication credentials for phpMyAdmin, making it particularly dangerous in environments where administrative access is not properly restricted. Organizations using this software are exposed to risks including data exfiltration, system compromise, and potential lateral movement within network environments where the vulnerable system exists.
Mitigation strategies should focus on immediate software updates to versions 3.5.8 or 4.0.0-rc3 and later, which contain proper filename validation and sanitization mechanisms. Administrators should also implement additional security controls such as restricting file upload capabilities, implementing proper file extension validation, and configuring web server directives to prevent execution of files with dangerous extensions in upload directories. Network segmentation and monitoring for suspicious file upload activities can provide additional layers of defense against exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other applications and systems within the organization's infrastructure.